External power source having an adjustable magnetic core and method of use

Abstract

External power source, and system and method using such external power source, for an implantable medical device having therapeutic componentry and a secondary coil operatively coupled to the therapeutic componentry. A primary coil is capable of inductively energizing the secondary coil when externally placed in proximity of the secondary coil. A repositionable magnetic core associated with the primary coil is capable of being repositioned by a user of the external power source. An indicator is capable of providing the user with information relative to coupling between the primary coil and the secondary coil as a function of repositioning of the repositionable magnetic core.

What is claimed is: 
     
       1. A method of transcutaneous energy transfer to a medical device implanted in a patient having a secondary charging coil using an external power source having a primary coil and a magnetic core associated with said primary coil, comprising the steps of:
 positioning said primary coil externally of said patient in proximity of said secondary coil; 
 then repositioning said magnetic core relative to said primary coil; 
 receiving indication of coupling between said primary coil and said secondary coil; and 
 stopping said repositioning step as a function of said receiving step. 
 
     
     
       2. A method as in  claim 1  wherein said primary coil and said magnetic core are contained in a housing and a non-magnetic retainer holds said magnetic core in said housing. 
     
     
       3. A method as in  claim 1  wherein said magnetic core comprises a circular ferrite disc, having a thickness, positioned inside said primary coil and an off-center ferrite post having a thickness greater than said thickness of said circular ferrite disc. 
     
     
       4. A method as in  claim 1  wherein said magnetic core is a ferrite core. 
     
     
       5. A method of charging a rechargeable power source of a medical device implanted in a patient, having a secondary charging coil operatively coupled to said rechargeable power source, using an external charger having a primary charging coil and a magnetic core associated with said primary charging coil, comprising the steps of:
 positioning said primary charging coil externally of said patient in proximity of said secondary charging coil; 
 then repositioning said magnetic core relative to said primary coil; 
 receiving indication of coupling between said primary coil and said secondary coil; and 
 stopping said repositioning step as a function of said receiving step. 
 
     
     
       6. A method as in  claim 5  further comprising the step of affixing said primary coil to said patient. 
     
     
       7. A method as in  claim 6  wherein said primary coil and said magnetic core are contained in a housing and wherein a non-magnetic retainer holds said magnetic core in said housing. 
     
     
       8. A method as in  claim 6  wherein said magnetic core comprises a circular ferrite disc, having a thickness, positioned inside said primary coil and an off-center ferrite post having a thickness greater than said thickness of said circular ferrite disc. 
     
     
       9. A method as in  claim 6  wherein said magnetic core is a ferrite core. 
     
     
       10. An external power source for an implantable medical device having therapeutic componentry and a secondary coil operatively coupled to said therapeutic componentry, comprising:
 a primary coil capable of inductively energizing said secondary coil when externally placed in proximity of said secondary coil; 
 a repositionable magnetic core associated with said primary coil being laterally repositionable with respect to an axis of said primary coil by a user of said external power source; and 
 an indicator providing said user with information relative to coupling between said primary coil and said secondary coil as a function of repositioning of said repositionable magnetic core. 
 
     
     
       11. An external power source as in  claim 10  further comprising:
 a housing containing said primary coil and said repositionable magnetic core; and 
 a non-magnetic retainer holding said magnetic core in said housing. 
 
     
     
       12. An external power source as in  claim 10  wherein said repositionable magnetic core comprises a circular ferrite disc, having a thickness, positioned inside said primary coil and an off-center ferrite post having a thickness greater than said thickness of said circular ferrite disc. 
     
     
       13. An external power source as in  claim 10  wherein said magnetic core is a ferrite core. 
     
     
       14. A charger for an implantable medical device having a rechargeable power source and a secondary charging coil operatively coupled to said rechargeable power source, comprising:
 a primary charging coil capable of inductively energizing said secondary coil when externally placed in proximity of said secondary coil; 
 a repositionable magnetic core associated with said primary coil being laterally repositionable with respect to an axis of said primary coil by a user of said charger; and 
 an indicator providing said user with information relative to coupling between said primary coil and said secondary coil as a function of repositioning of said repositionable magnetic core. 
 
     
     
       15. A charger as in  claim 14  further comprising:
 a housing containing said primary coil and said repositionable magnetic core; and 
 a non-magnetic retainer holding said magnetic core in said housing. 
 
     
     
       16. A charger as in  claim 14  wherein said repositionable magnetic core comprises a circular ferrite disc, having a thickness, positioned inside said primary coil and an off-center ferrite post having a thickness greater than said thickness of said circular ferrite disc. 
     
     
       17. A charger as in  claim 14  wherein said magnetic core is a ferrite core. 
     
     
       18. An external power source for an implantable medical device having therapeutic componentry and a secondary coil operatively coupled to said therapeutic componentry, comprising:
 a primary coil capable of inductively energizing said secondary coil when externally placed in proximity of said secondary coil; 
 a rotatable magnetic core placed off-center with respect to said primary coil and rotatable by a user of said external power source; and 
 an indicator providing said user with information relative to coupling between said primary coil and said secondary coil as a function of rotating of said rotatable magnetic core. 
 
     
     
       19. An external power source as in  claim 18  further comprising:
 a housing containing said primary coil and said rotatable magnetic core; and 
 a non-magnetic retainer holding said magnetic core in said housing. 
 
     
     
       20. An external power source as in  claim 18  wherein said rotatable magnetic core comprises a circular ferrite disc, having a thickness, positioned inside said primary coil and an off-center ferrite post having a thickness greater than said thickness of said circular ferrite disc. 
     
     
       21. An external power source as in  claim 18  wherein said magnetic core is a ferrite core. 
     
     
       22. A system for transcutaneous energy transfer, comprising:
 an implantable medical device, comprising:
 a therapeutic componentry; and 
 a secondary coil operatively coupled to said therapeutic componentry; and 
 
 an external power source, comprising:
 a primary coil capable of inductively energizing said secondary coil when externally placed in proximity of said secondary coil; 
 a repositionable magnetic core associated with said primary coil being laterally repositionable with respect to an axis of said primary coil by a user of said system; and 
 an indicator providing said user with information relative to coupling between said primary coil and said secondary coil as a function of repositioning of said repositionable magnetic core. 
 
 
     
     
       23. A system as in  claim 22  further comprising:
 a housing containing said primary coil and said repositionable magnetic core; and 
 a non-magnetic retainer holding said magnetic core in said housing. 
 
     
     
       24. A system as in  claim 22  wherein said repositionable magnetic core comprises a circular ferrite disc, having a thickness, positioned inside said primary coil and an off-center ferrite post having a thickness greater than said thickness of said circular ferrite disc. 
     
     
       25. A system as in  claim 22  wherein said magnetic core is a ferrite core. 
     
     
       26. A system for charging, comprising:
 an implantable medical device, comprising:
 a rechargeable power source; and 
 a secondary charging coil operatively coupled to said rechargeable power source; and 
 
 an external charger, comprising:
 a primary charging coil capable of inductively energizing said secondary coil when externally placed in proximity of said secondary coil; 
 a repositionable magnetic core associated with said primary coil being laterally repositionable with respect to an axis of said primary coil by a user of said charger; and 
 an indicator providing said user with information relative to coupling between said primary coil and said secondary coil as a function of repositioning of said repositionable magnetic core. 
 
 
     
     
       27. A system as in  claim 26  further comprising:
 a housing containing said primary coil and said repositionable magnetic core; and 
 a non-magnetic retainer holding said magnetic core in said housing. 
 
     
     
       28. A system as in  claim 26  wherein said repositionable magnetic core comprises a circular ferrite disc, having a thickness, positioned inside said primary coil and an off-center ferrite post having a thickness greater than said thickness of said circular ferrite disc. 
     
     
       29. A system as in  claim 26  wherein said magnetic core is a ferrite core. 
     
     
       30. A system for charging, comprising:
 an implantable medical device, comprising:
 therapeutic componentry; and 
 a secondary charging coil operatively coupled to said therapeutic componentry; and 
 
 an external power source, comprising:
 a primary coil capable of inductively energizing said secondary coil when externally placed in proximity of said secondary coil; 
 a rotatable magnetic core placed off-center inside said primary coil rotatable by a user of said system; and 
 an indicator providing said user with information relative to coupling between said primary coil and said secondary coil as a function of rotating of said rotatable magnetic core. 
 
 
     
     
       31. A system as in  claim 30  further comprising:
 a housing containing said primary coil and said rotatable magnetic core; and 
 a non-magnetic retainer holding said magnetic core in said housing. 
 
     
     
       32. A system as in  claim 30  wherein said rotatable magnetic core comprises a circular ferrite disc, having a thickness, positioned inside said primary coil and an off-center ferrite post having a thickness greater than said thickness of said circular ferrite disc. 
     
     
       33. A system as in  claim 30  wherein said magnetic core is a ferrite core.